CARRIAGE OF GOODS - CARRIAGE OF GOODS BY ROAD - TRANSPORT TARIFFS - BRACKET TARIFFS - DETERMINATION IN THE CURRENCIES OF THE MEMBER STATES CONCERNED - VARIATION IN THE RATE OF EXCHANGE - OBLIGATION ON THE PART OF THE MEMBER STATES TO AMEND THE BRACKETS - SCOPE - DISCRETION OF THE MEMBER STATES SUBJECT TO REVIEW BY THE NATIONAL COURTS ( EEC TREATY , ART . 177 ; REGULATION NO 1174/68 OF THE COUNCIL )